Why is there a grinding sound coming from the rear passenger side when I drive slow?

I drive a 96 Ford Mustang V6. For the past couple weeks when I'm driving really slow, like between 10-20mph I hear a grinding sound coming from the back passenger side. When I go over 20 the sound goes away. Brake response is normal. It doesn't make the sound when I apply the brakes. I initially thought it was a bad rotor but I've had that problem before and it only sounded like that when applying the brakes(like a squealing). Could it be a loose bearing or some debris stuck up underneath somewhere? Worst case scenario and it's a bad rotor, estimate of how much to repair at Firestone where I have a store credit card?

Wanting to widen my 2007 Ford Mustang GT Bullit Rims?

I have a 2007 Ford Mustang Grey Alloy GT

Ever since i got it i had always wanted to widen the wheel i just have no clue how i could widen them. The Stock Bullit rims are not wide enough to put wider tires in the rear so i want to widen the bullit rims so that i can fit 345 wide tires in the rear, i'm doing this for looks not for performance. How can i do this?

Thermostat lower housing replacement?

I currently own a 2000 Ford Mustang gt and have a leak in my lower thermostat housing. I'm having great difficultly In finding out how to remove the lower housing. I honestly don't think it's removable from the looks of it. Are there any 96-04 mustang Experts out that that can assist me? Thanks in advance! Thermostat lower housing replacement

College freshman with a mustang?

I'm thinking of purchasing a 2006 Ford Mustang convertible. It has about 93,000 miles on it and is a V6. The asking price is around $6,800.

Questions:
Is it worth it? I d like to visit home possibly once a month and it's a two hour drive.

How much would insurance be considering it is a Mustang and I'm 18 years old?(19 in two months if that makes a difference).

Should I look at other cars? Suggestions?
I love mustangs and now is my chance to actually get one. I'm not into racing or anything like that.

Do I need some king of grease to replace spark plugs?

I'm going to replace the spark plugs of my 04 Ford Mustang V6 3.8 L. I have the tools and spark plugs. I know the GAP is 0.054. However, someone told me I need grease to addo to the spark plugs and wires. Is that true? If so, what kind and how to apply it.